CU-Boulder scientists prepare for Mercury fly-by

NASA's Messenegr spacecraft, toting an $8.7 million University of Colorado at Boulder instrument, will make its third and final fly-by of Mercury Tuesday.

The spacecraft will zip within 142 miles of the planet's surface at more than 100,000 mph, taking high-resolution color images of the surface terrain.

The probe will also be making ultraviolet and visible light measurements of the planet's surface, its atmosphere and a comet-tailed gas cloud 25,000 miles long that trails behind the planet.

Messenger is carrying seven instruments including CU-Boulder's Mercury Atmospheric and Surface Composition Spectrometer, or MASCS. CU-Boulder Senior Research Associate William McClintock said, "We will be pointing at each individual target from several different angles during the flyby, which will allow us to collect more data."

The MASCS team is especially interested in surface deposits spotted by the camera during Messenger's previous flybys, McClintock said.